Forsythia mandschurica A less common, compact and early flowering Forsythia, large yellow flowers appear on bare stems in March and April. Excellent Autumn colour. Site: Fairly shelteredPosition: Full sun to partial shadeSoil: Moist, but well-drained soilSeasons of interest: Early Spring flowers; Autumn colourHardiness: HardyHeight: 3-5ft (1-1.5m) Spread: 3-5ft (1-1.5m)